As noted in my other posts... http://bimmerforums.com/forum/showthread.php?t=383365
my CE light has been on with the code 1234, vehicle speed sensor. When I took out the old speed sensor I noticed the end with the magnet on it was covered in little metal shavings (stock diff... 130k miles) I figured this was messing up the reading and causing the CE light. I have since replaced the plug in the differential (the v.s.s.) but did not reset the computer.. it did not fix my problem, no big surprise. When I unplugged the battery for a few minutes and fired it up again I had no CE light and all of the symptoms noted in the other thread were gone.
After a few miles of driving the light came on again with the same code, same problems. I took out the v.s.s. and it had a very small amount of metal on it, no where near as many as before but they were there so I cleaned it and re-installed it. Also undid the battery, resetting the computer. When I turned it on anverything was fine no CE light and no problems.
After a few miles the light came on again and so did the driveability problems. This time I did not clean the v.s.s., I just simply reset the computer again. Once again the CE light and problems went away for a few miles before returning.
I have come to the conclusion that maybe the vehicle speed sensor isnt the problem and something else is. .... The only obvious thing i can see wrong with my car is a green wire hanging loose in the drivers side frontwheel well which i am told is just a brake pad sensor. could this be my real problem?? What else could be causing these symptoms???? I am at my wits end
1/4 mile in 13.1 @ 106++ (calculators put this at 0-60 in "4.21" seconds.)
I can't see that loose wire or the VSS as being a cause of your drivability issues. My suspicion is that the hard boot of the ECU from the battery disconnect is what's clearing the 6500rpm problem. Just to be sure I'd replace the VSS, clear the fault code and see if that helps.
The car makes it possible, but the driver makes it happen.
Jim Levie, Huntsville, AL
If those metal shavings keep messing up the sensor, then you may have a major diff problem.
"Way-dull" Racing #74
Originally Posted by thejlevie
That is what I did. Problems were fixed for a few minutes but they would always return.
1/4 mile in 13.1 @ 106++ (calculators put this at 0-60 in "4.21" seconds.)
Sorry, I misunderstood. It sounded to me like you'd pulled the VSS, cleaned it, and replaced it. I don't know enough about the internals of the VSS to be able to say how much accumulated metal shavings would interfere with it's operation. but it doesn't seem to me like there'd be enough in the diff to fail the sensor unless there's a serious problem in the differential. At the least I think I'd drain the diff, refill it, drive it enough to get it hot, then drain and refill once more. If there's a lot of metal shavings in the oil I'd be seriously considering a replacement.Originally Posted by xjeeper
But even so I don't know of a reason that the VSS would cause the drivability problems. I suspect that's something else. And it may be hard to figure out with the mods you've done. It's probably time to seek professional help, preferably via an indie shop with lots of experience in M3's, or even better one that does some prep work on M3 racers.
The car makes it possible, but the driver makes it happen.
Jim Levie, Huntsville, AL
fixed it!!! The problem turned out to me a torn abs sensor wire on the right rear.
1/4 mile in 13.1 @ 106++ (calculators put this at 0-60 in "4.21" seconds.)
How could an ABS sensor wire cause the hesitation before redline?
EDIT: Also, did you have an ABS light on in your cluster?
Last edited by SQ Bimmer; 05-29-2006 at 11:06 PM.
no abs light
It seems that nobody knows how or why an abs sensor can effect the motor but for whatever reason it does.
1/4 mile in 13.1 @ 106++ (calculators put this at 0-60 in "4.21" seconds.)
OK, well then, I am going to change out all my ABS sensors and hope for the best.
BTW - You ever get a check engine light?
yup code 1234 vehicle speed senor. Guess the ABS sensor does measure wheel speed so it makes sense to get that light. kinda...
1/4 mile in 13.1 @ 106++ (calculators put this at 0-60 in "4.21" seconds.)
I'm gonna be tackling this job shortly. I will post up my results. I am also going to be changing my knock sensors, but I will do one "fix" at a time, and see what happens.
OK, I changed my VSS with the VSS from my 318 diff that did not throw a code before my swap. Unplugged battery for 5 mins, started car up and drove, CEL came right back. First got a code 1281 (DME memory supply, normal) then after a couple drives got a 1234 again.
ABS sensors next...
Known working ABS sensors at all 4 corners and, as psoted above, known working VSS sensor is in the diff. Reset ECU a million times, still no fix for my hesitation, however, code 1234 doesn't come up anymore, and code 1226 (knock sensor 2) is back in it's place (original code was knock sensor, but that code came up well before my hesitation issues.).
So, I am going to change out my knock sensors tomorrow, will report back to this thread...
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